OBJECTIVE: To summarize the research progress on the mechanism related to traumatic brain injury (TBI) to promote fracture healing, and to provide theoretical basis for clinical treatment of fracture non-union. METHODS: The research literature on TBI to promote fracture healing at home and abroad was reviewed, the role of TBI in fracture healing was summarized from three aspects of nerves, body fluids, and immunity, to explore new ideas for the treatment of fracture non-union. RESULTS: Numerous studies have shown that fracture healing is faster in patients with fracture combined with TBI than in patients with simple fracture. It is found that the expression of various cytokines and hormones in the body fluids of patients with fracture and TBI is significantly higher than that of patients with simple fracture, and the neurofactors released by the nervous system reaches the fracture site through the damaged blood-brain barrier, and the chemotaxis and aggregation of inflammatory cells and inflammatory factors at the fracture end of patients with combined TBI also differs significantly from those of patients with simple fracture. A complex network of humoral, neural, and immunomodulatory networks together promote regeneration of blood vessels at the fracture site, osteoblasts differentiation, and inhibition of osteoclasts activity. CONCLUSION TBI promotes fracture healing through a complex network of neural, humoral, and immunomodulatory, and can treat fracture non-union by intervening in the perifracture microenvironment.
Humans ; Fracture Healing/physiology* ; Brain Injuries/metabolism* ; Brain Injuries, Traumatic ; Fractures, Bone ; Osteogenesis

Rats ; Animals ; Astrocytes ; Exosomes/metabolism* ; Brain Injuries, Traumatic/metabolism* ; Biological Transport

OBJECTIVE: To investigate the protective effect against intestinal mucosal injury in rats following traumatic brain injury (TBI) and explore the underlying mechanism. METHODS: SD rat models of TBI were established by fluid percussion injury (FPI), and the specimens were collected at 12, 24, 48, and 72 h after TBI. Another 15 rats were randomly divided into shamoperated group (n=5), TBI with saline treatment (TBI+NS) group (n=5), and TBI with PD treatment (TBI+PD) group (treated with 30 mg/kg PD after TBI; n=5). Body weight gain and fecal water content of the rats were recorded, and after the treatments, the histopathology of the jejunum was observed, and the levels of D-lactic acid (D-LAC), diamine oxidase (DAO), ZO-1, claudin-5, and reactive oxygen species (ROS) were detected. Lipid peroxide (LPO) and superoxide dismutase (SOD) 2 content, jejunal pro-inflammatory factors (IL-6, IL-1β, and TNF- α), Sirt1 activity, SOD2 and HMGB1 acetylation level were also determined after the treatments. RESULTS: The rats showed significantly decreased body weight and fecal water content and progressively increased serum levels of D-LAC and DAO after TBI (P < 0.05) with obvious jejunal injury, significantly decreased expression levels of ZO-1 and claudin-5, lowered SOD2 and Sirt1 activity (P < 0.05), increased expression levels of LPO, ROS, and pro-inflammatory cytokines, and enhanced SOD2 and HMGB1 acetylation levels (P < 0.05). Compared with TBI+NS group, the rats in TBI+PD group showed obvious body weight regain, increased fecal water content, reduced jejunal pathologies, decreased D-LAC and DAO levels (P < 0.05), increased ZO-1, claudin-5, SOD2 expression levels and Sirt1 activity, and significantly decreased ROS, LPO, pro-inflammatory cytokines, and acetylation levels of SOD2 and HMGB1 (P < 0.05). CONCLUSION PD alleviates oxidative stress and inflammatory response by activating Sirt1-mediated deacetylation of SOD2 and HMGB1 to improve intestinal mucosal injury in TBI rats.
Animals ; Brain Injuries, Traumatic ; Glucosides/pharmacology* ; HMGB1 Protein/metabolism* ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism* ; Stilbenes/pharmacology* ; Superoxide Dismutase/metabolism*

The purpose of the present study was to investigate the effect of glutamate scavenger oxaloacetate (OA) combined with CGS21680, an adenosine A2A receptor (A2AR) agonist, on acute traumatic brain injury (TBI), and to elucidate the underlying mechanisms. C57BL/6J mice were subjected to moderate-level TBI by controlled cortical impact, and then were treated with OA, CGS21680, or OA combined with CGS21680 at acute stage of TBI. At 24 h post TBI, neurological severity score, brain water content, glutamate concentration in cerebrospinal fluid (CSF), mRNA and protein levels of IL-1β and TNF-α, mRNA level and activity of glutamate oxaloacetate aminotransferase (GOT), and ATP level of brain tissue were detected. The results showed that neurological deficit, brain water content, glutamate concentration in CSF, and the inflammatory cytokine IL-1β and TNF-α production were exacerbated in CGS21680 treated mice. Administrating OA suppressed the rise of both glutamate concentration in CSF and brain water content, and elevated the ATP level of cerebral tissue. More interestingly, neurological deficit, brain edema, glutamate concentration, IL-1β and TNF-α levels were ameliorated significantly in mice treated with OA combined with CGS21680. The combined treatment exhibited better therapeutic effects than single OA treatment. We also observed that GOT activity was enhanced in single CGS21680 treatment group, and both the GOT mRNA level and GOT activity were up-regulated in early-stage combined treatment group. These results suggest that A2AR can improve the efficiency of GOT and potentiate the ability of OA to metabolize glutamate. This may be the mechanism that A2AR activation in combination group augmented the neuroprotective effect of OA rather than aggravated the brain damages. Taken together, the present study provides a new insight for the clinical treatment of TBI with A2AR agonists and OA.
Adenosine A2 Receptor Agonists/therapeutic use* ; Adenosine Triphosphate ; Animals ; Brain Injuries/metabolism* ; Brain Injuries, Traumatic/metabolism* ; Glutamic Acid ; Mice ; Mice, Inbred C57BL ; Neuroprotective Agents/therapeutic use* ; Oxaloacetic Acid/therapeutic use* ; RNA, Messenger ; Receptor, Adenosine A2A/metabolism* ; Tumor Necrosis Factor-alpha/genetics* ; Water

The brain pericyte is a unique and indispensable part of the blood-brain barrier (BBB), and contributes to several pathological processes in traumatic brain injury (TBI). However, the cellular and molecular mechanisms by which pericytes are regulated in the damaged brain are largely unknown. Here, we show that the formation of neutrophil extracellular traps (NETs) induces the appearance of CD11b⁺ pericytes after TBI. These CD11b⁺ pericyte subsets are characterized by increased permeability and pro-inflammatory profiles compared to CD11b^- pericytes. Moreover, histones from NETs by Dectin-1 facilitate CD11b induction in brain pericytes in PKC-c-Jun dependent manner, resulting in neuroinflammation and BBB dysfunction after TBI. These data indicate that neutrophil-NET-pericyte and histone-Dectin-1-CD11b are possible mechanisms for the activation and dysfunction of pericytes. Targeting NETs formation and Dectin-1 are promising means of treating TBI.
Blood-Brain Barrier/metabolism* ; Brain/pathology* ; Brain Injuries, Traumatic/metabolism* ; Extracellular Traps/metabolism* ; Histones ; Humans ; Lectins, C-Type ; Pericytes/pathology*

Traumatic brain injury (TBI) contributes to the key causative elements of neurological deficits. However, no effective therapeutics have been developed yet. In our previous work, extracellular vesicles (EVs) secreted by stem cells from human exfoliated deciduous teeth (SHED) offered new insights as potential strategies for functional recovery of TBI. The current study aims to elucidate the mechanism of action, providing novel therapeutic targets for future clinical interventions. With the miRNA array performed and Real-time PCR validated, we revealed the crucial function of miR-330-5p transferred by SHED-derived EVs (SHED-EVs) in regulating microglia, the critical immune modulator in central nervous system. MiR-330-5p targeted Ehmt2 and mediated the transcription of CXCL14 to promote M2 microglia polarization and inhibit M1 polarization. Identified in our in vivo data, SHED-EVs and their effector miR-330-5p alleviated the secretion of inflammatory cytokines and resumed the motor functional recovery of TBI rats. In summary, by transferring miR-330-5p, SHED-EVs favored anti-inflammatory microglia polarization through Ehmt2 mediated CXCL14 transcription in treating traumatic brain injury.
Animals ; Brain Injuries, Traumatic/therapy* ; Chemokines, CXC/metabolism* ; Extracellular Vesicles/metabolism* ; Histocompatibility Antigens/metabolism* ; Histone-Lysine N-Methyltransferase/metabolism* ; Humans ; MicroRNAs/metabolism* ; Microglia/metabolism* ; Rats ; Stem Cells/metabolism*

OBJECTIVE: To observe the impacts of electroacupuncture (EA) on neurological function, the pathological morphology in brain tissue, apoptosis level and the protein expressions of apoptosis-related cytochrome C (Cyt-C) and cysteine aspartic acid protease-9 (Caspase-9) in the rats with traumatic brain injury (TBI) and explore the potential mechanism of EA in treatment of TBI. METHODS: A total of 70 clean-grade SD mice were randomized into a blank group (8 rats), a sham-operation group (8 rats), a model group (27 rats) and an EA group (27 rats). In terms of interventions of 3, 7 and 14 days, 3 subgroups were divided in the model group and the EA group successively, 9 rats in each subgroup. The modified Feeney free-fall percussion method was adopted to establish TBI models of rats. In the sham-operation group, only the skull was exposed and drilled and no free-fall percussion was exerted. One day after modeling, EA was given in the rats of EA group at "Shuigou" (GV 26), "Baihui" (GV 20) and "Neiguan" (PC 6) and "Zusanli" (ST 36) on the affected side, with intermittent wave, 2 Hz in frequency, once daily, 10 min each time, for 3, 7 and 14 days successively. Separately, on the day 3, 7 and 14 of intervention, the modified neurological severity scale (mNSS) was used to evaluate the degree of neurological function injury in the rats, HE staining and Nissl staining were to observe the pathological and morphological changes in brain tissue, TUNEL method was to observe the level of apoptosis in brain tissue and immunohistochemistry (IHC) method and Western blot were to determine the protein expressions of Cyt-C and Caspase-9 in brain tissue. RESULTS: Compared with the sham-operation group, on the day 3, 7 and 14 of intervention, mNSS scores were increased obviously in the rats of the model group respectively (<0.01). Compared with the model group, on the day 3, 7 and 14 of intervention, mNSS scores were reduced in the rats of the EA group respectively (<0.05). On day 3 of intervention, in brain injury region of the rats in the model group and the EA group, gross tissue necrosis, nuclear fragmentation, consolidation and obvious vacuolar changes, reduced Nissl bodies and scattered arrangement were found. On day 7 and 14 of intervention, in the model group and the EA group, the new connective tissue filling and normal cells were visible and Nissl bodies increased. The overall repair and Nissl body quantity in the EA group were better than the model group. Compared with the sham-operation group, on day 3, 7 and 14 of intervention, the numbers of apoptotic cells were increased obviously in the model group (<0.01) and they were reduced in the EA group as compared with the model group (<0.05). Compared with the sham-operation group, on day 3, 7 and 14 of intervention, the protein expressions of Cyt-C and Caspase-9 in damaged brain tissue were all increased obviously in the model group (<0.01) and they were all reduced in the EA group as compared with the model group successively (<0.05). CONCLUSION Electroacupuncture remarkably improves the condition in the neurological function injury and reduces apoptosis degree in TBI model rats, which is likely related to the down-regulation of the protein expressions of Cyt-C and Caspase-9 in damaged brain tissue and further to bring the impacts on mitochondria mediated apoptosis process.
Animals ; Apoptosis ; Brain Injuries, Traumatic ; therapy ; Caspase 9 ; metabolism ; Cytochromes c ; metabolism ; Electroacupuncture ; Random Allocation ; Rats ; Rats, Sprague-Dawley

Objective To study the characteristics of positive expression of integrin β1 in the rat brain tissue of two kinds of traumatic brain injury models and to explore the feasibility of inferring the mode of traumatic brain injury using the positive expression of integrin β1. Methods The occipital region of rats was hit by hydraulic impact method and pendulum striking method to produce two closed brain injury models of linear and rotation acceleration respectively, then 120 SD rats were randomly divided into linear acceleration injury group, rotation acceleration injury group, sham operation group and normal control group. Immunohistochemistry staining and Western blotting method were used to detect the positive expression of integrin β1 in different parts of the brain tissue at 30 min, 3 h, 6 h, 12 h, 3 d and 7 d after rat injury. The data was processed statistically by SPSS 18.0 software. Results The positive expression of integrin β1 was detected 30 min after brain injury and reached the peak 6 h after brain injury. With the extension of injury time, the expression tended to enhance. At the same time points after injury, the differences in the positive expression of integrin β1 between the linear acceleration injury group and the rotation acceleration injury group in the occipital strike point and thalamus had no statistical significance （ P>0.05）, but the differences in the expression of integrin β1 in the frontal lobe and brain stem had statistical significance （P<0.05）. Conclusion The characteristics of positive expression of integrin β1 in brain tissue can be used to infer the strike point and the manner of injury and has application value for the reconstruction of craniocerebral injury process.
Animals ; Brain/metabolism* ; Brain Injuries ; Brain Injuries, Traumatic ; Integrin beta1/metabolism* ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo examine the effect of icariin (ICA) on the cognitive impairment induced by traumatic brain injury (TBI) in mice and the underlying mechanisms related to changes in hippocampal acetylation level.

METHODSThe modifified free-fall method was used to establish the TBI mouse model. Mice with post-TBI cognitive impairment were randomly divided into 3 groups using the randomised block method (n=7): TBI (vehicle-treated), low-dose (75 mg/kg) and high-dose (150 mg/kg) of ICA groups. An additional sham-operated group (vehicle-treated) was employed. The vehicle or ICA was administrated by gavage for 28 consecutive days. The Morris water maze (MWM) test was conducted. Acetylcholine (ACh) content, mRNA and protein levels of choline acetyltransferase (ChAT), and protein levels of acetylated H3 (Ac-H3) and Ac-H4 were detected in the hippocampus.

RESULTSCompared with the sham-operated group, the MWM performance, hippocampal ACh content, mRNA and protein levels of ChAT, and protein levels of Ac-H3 and Ac-H4 were signifificantly decreased in the TBI group (P<0.05). High-dose of ICA signifificantly ameliorated the TBI-induced weak MWM performance, increased hippocampal ACh content, and mRNA and protein levels of ChAT, as well as Ac-H3 protein level compared with the TBI group (P<0.05).

CONCLUSIONICA improved post-TBI cognitive impairment in mice by enhancing hippocampal acetylation, which improved hippocampal cholinergic function and ultimately improved cognition.

Acetylation ; Acetylcholine ; metabolism ; Animals ; Brain Injuries, Traumatic ; complications ; Choline O-Acetyltransferase ; genetics ; metabolism ; Cognitive Dysfunction ; drug therapy ; etiology ; Flavonoids ; chemistry ; pharmacology ; therapeutic use ; Hippocampus ; pathology ; Histones ; metabolism ; Homeostasis ; drug effects ; Male ; Maze Learning ; drug effects ; Mice ; RNA, Messenger ; genetics ; metabolism

PURPOSETo investigate the effects of estrogen G protein-coupled receptor 30 (GPR30) agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury (TBI).

METHODSMale SD rats were randomly divided into sham group, TBI + vehicle group, TBI + G1 group. Experimental moderate TBI was induced using Feeney's weigh-drop method. G1 (100μg/kg) or vehicle was intravenously injected from femoral vein at 30 min post-injury. Rats were sacrificed at 24 h after injury for detection of neuronal apoptosis and microglia polarization. Neuronal apoptosis was assayed by immunofluorescent staining of active caspase-3. M1 type microglia markers (iNOS and IL-1β) and M2 type markers (Arg1 and IL-4) were examined by immunoblotting or ELISA. Total protein level of Akt and phosphorylated Akt were assayed by immunoblotting.

RESULTSG1 significantly reduced active caspase-3 positive neurons in hippocampus. Meanwhile G1 increased the ratio of Arg1/iNOS. IL-1β production was decreased but IL-4 was increased after G1 treatment. G1 treatment also increased the active form of Akt.

CONCLUSIONSGPR30 agonist G1 inhibited neuronal apoptosis and favored microglia polarization to M2 type.

Animals ; Apoptosis ; drug effects ; Brain Injuries, Traumatic ; drug therapy ; pathology ; Cell Polarity ; Hippocampus ; drug effects ; Interleukin-1beta ; biosynthesis ; Male ; Microglia ; drug effects ; Neurons ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; agonists